91008173 has 2 divisors, whose sum is σ = 91008174. Its totient is φ = 91008172.

The previous prime is 91008143. The next prime is 91008179. The reversal of 91008173 is 37180019.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 76772644 + 14235529 = 8762^2 + 3773^2 .

It is a cyclic number.

It is not a de Polignac number, because 91008173 - 2⁶ = 91008109 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (91008179) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45504086 + 45504087.

It is an arithmetic number, because the mean of its divisors is an integer number (45504087).

Almost surely, 2^91008173 is an apocalyptic number.

It is an amenable number.

91008173 is a deficient number, since it is larger than the sum of its proper divisors (1).

91008173 is an equidigital number, since it uses as much as digits as its factorization.

91008173 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1512, while the sum is 29.

The square root of 91008173 is about 9539.8203861498. The cubic root of 91008173 is about 449.8076099396.

The spelling of 91008173 in words is "ninety-one million, eight thousand, one hundred seventy-three".